The present invention relates generally to toy vehicles and, more particularly, to a toy vehicle painted with a paint containing thermochromic material which changes color as the temperature of the vehicle varies.
In the past, a variety of toys have been developed with color-changing features using thermochromic or light-sensitive materials embedded or mixed in plastic, printed on paper or plastic, or impregnated in fibers used for clothing, doll hair, plush figures, or the like. For example, U.S. Pat. Nos. 4,560,604 issued to Shimizu, et al on Dec. 24, 1985 (coating fibers used for stuffed toys with thermochromic material); 4,134,853 issued to Ehrlich, et al on Jan. 16, 1979 (photochromic composition combined with moldable materials for forming toys); and 3,980,300 issued to Hornsby, Jr. on Sept. 14, 1976 (layer of liquid crystalline material used for ball) which disclose the use of such materials in toys. British Patent No. GB 2,066,089A issued to Rickson on July 8, 1981 describes the use of temperature-sensitive cholesteric liquid crystal material for changing the color of the eyes of a doll. U.S. Pat. No. 3,382,607 issued to Ryan, et al on May 14, 1968 discloses a figure toy having synthetic hair fibers impregnated with an indicator dye which changes color in response to contact with liquids of different pH concentrations.
Thermochromic materials are disclosed in U.S. Pat. Nos. 4,567,019 issued to Lawton on Jan. 28, 1986 and 4,421,560 issued to Kito, et al on Dec. 20, 1983. Heat-sensitive recording materials are described in U.S. Pat. Nos. 4,611,072 issued to Nachbur, et al; 4,462,616 issued to Shanton on July 31, 1984; and 4,444,819 issued to Maruta, et al.
None of the above patents discloses a toy vehicle painted with a paint containing thermochromic material which is capable of changing color as the temperature of the vehicle varies. Since the toy vehicle is painted, such a toy vehicle, especially a miniature die-cast vehicle, provides numerous play options. For example, a child could pretend that such a toy vehicle is being painted by immersing it in heated or cold water causing the color of the vehicle to change. A child could also vary the color of such a vehicle using heated or cold air, ice, heated pens, heated brushes, light bulbs, heat blankets, or the heat of his or her hands The toy vehicle could be made out of any material such as metal or plastic. Accordingly, there is a need in the toy manufacturing arts for such a toy vehicle.